RSS and news feeds for agents

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Even though readOnlyHint and idempotentHint are already present, the description adds real behavioral detail: it enumerates the exact sources scanned (link tags, Link header, feed-shaped links, common paths, legacy feeds), notes the ordering ('deepest path prefix first'), and reveals that every attempted rung is returned. This is valuable information beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences carry a substantial amount of information with no filler. The primary purpose is front-loaded, followed by the method breakdown and then explicit use cases. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with three parameters and no output schema, the description covers the discovery process, ordering, and return behavior ('every rung tried is returned') well. It does not specify the exact response format or error/failure behavior, but this is a minor gap for a read-only discovery tool with already rich schema descriptions.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema already documents all three parameters with clear descriptions, so the baseline is 3. The description vaguely aligns with the 'all' parameter ('want all of a site's feeds') and the task_context parameter ('tunes the result'), but it does not add meaning beyond what the schema descriptions already provide.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description begins with a specific verb and resource ('Find the RSS/Atom/JSON feed(s) of a site') and elaborates with concrete detection methods. It also differentiates from the sibling feed_items by describing the debugging use case ('feed_items missed and you want to see why').

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use the tool: 'Use when you need a feed URL, want all of a site's feeds, or feed_items missed and you want to see why.' It names the feed_items alternative and ties usage to a specific symptom, giving an agent clear routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate readOnly, openWorld, and idempotent behavior. The description adds useful behavioral detail beyond annotations: items are deduplicated, sorted newest first, text is bounded, and the discovery ladder runs and reports how the URL resolved. This helps the agent anticipate output shape and edge cases.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, with the core behavior front-loaded and every clause contributing useful information. The output field list is compact and the use case is stated last without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the output format, ordering, dedup, date filtering, URL flexibility, and resolution reporting. The schema fills in parameter details for since, max_chars, and task_context. It is mostly complete for a read-only tool, though it could briefly mention that limit defaults to 20 and max 100.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 80%, so a baseline of 3 applies. The description adds meaningful param-related nuance: it explains that url may be a feed URL or a plain site URL and that a discovery ladder resolves it. It also implicitly describes the 'since' behavior and bounded text, though it does not mention limit or max_chars by name.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Read a feed') and a clear resource, enumerates the returned fields, and states ordering, dedup, and optional date filtering. It also gives a concrete use case ('what is new on X'), which distinguishes it from siblings like feed_find and news_search.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Use for "what is new on X"', giving clear context for when the tool is appropriate. It also clarifies that url can be a feed URL or a site URL, but it does not explicitly contrast with feed_find or news_search or state when not to use this tool.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description discloses substantial behavior beyond the readOnly/openWorld annotations: keyless access, parallel engine queries, reciprocal-rank fusion, deduplication by normalized URL, same-story grouping under also_on, and the meaning of 'via: both' as the strongest signal. No contradiction with annotations exists.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and information-dense: one sentence establishes purpose and behavior, and one short clause provides routing guidance. Every phrase earns its place, with the most important scoping information front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Even without an output schema, the description tells an agent what results will contain: deduplicated items, same-story variants under also_on, publisher attribution, and which engines carried each item including the strongest signal via: both. Combined with the readOnly annotation, this is sufficient for confident tool selection and interpretation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides useful descriptions for lang, when, region, and task_context, and the remaining two parameters (query, limit) are self-evident. The tool description itself adds almost no parameter-level guidance, so it contributes little beyond the schema, but the schema coverage is high enough that this is only a minor gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource ('news search') and defines the exact scope: Google News RSS and Bing News RSS in parallel, fused and deduplicated. It also explicitly names a sibling (feed_items) to contrast with, so an agent can distinguish this tool from alternatives without opening schemas.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives an explicit canonical use case ('what is the news about X') and explicitly says to use feed_items for one site's own posts. This is clear when-to-use and when-not-to-use routing, satisfying the strongest bar for this dimension.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.